Flotation agent and method of making same



PAE

a ED STATES FLOTA'I'ION AGENT AND METHOD OF MAKING SAME.

K0 Drawing.

To all whom it may concern:

lie it known that we .iiicinilluiscu and Manx llinscn, citizens of thel nited States, and residents of New York, in the county of New Yorc and State of New York have invented certain new and useful Improvements in Flotation Agents and Methods of Making the Fianna of which the following is a specification. i

The invention relates to iinprovements in ore flotation agents andmiethodot' making the same, and particularly thoseof the aromatic amine class. It has been customary to make an ore flotation compound by taking pure naphthalene and nitrating and reducing the same to form alpha-naphthylamine and taking pure xylene and nitrating and re.- dueing the same to form the amido suhstitution product thereof. and then mixing the substantially pure amines to form a flotation compound eon'imonly known as x-cake flotation reagent. It has hitherto heen assumed that these n'iaterials must he made substantially pure before mixture in order to get the desired results, and furthermore in the nitration and reduction of naphthalene to make naphthylamine it has been in a solid i state and therefore dill'icult to treat and separate from the reaction material and acconn panyirng impurities formed,

We have discovered that the usual impurities aecompanyim such erude aromatic compounds, and particularly the impurities accompanying crude commercial naphthalene and xylene. when subjected to the usual treatment in making the corresponding amines, d iiot decrease the flotation value of the na'gilitliylamine and xylidine, but they tend ratl'li r to increase the flotation value. We have furthermore discovered that great eommereial ad 'antages result from the mixinn: oi" the raw materials such as naphthalene and xylene and then nitration and reducing the mixture to form the mixed amines, in stead of nitraiin'g: and reducing them sepa r'ateiy.

While the invention in its broaderaspects not limited to the particular'aromatio amines used, nor to the, particularchemical reagents used, \i'e prefer to use a mixture of naphthylamine and xylidine. prepared trom crude naphthaleneam'l xylene hy' the us" of well known nitrating and reducing re gents. ."icoordiugly we set out helow one specific example. from whi-eh those skilled in the art will imderstand the nature of the invention and its advantages"? Specification of Letters Patent.

Patented Feb. 258, 1922.

application filed June 30,1920. Serial No. 392,996.

idly relatively large quantities of liquid ma 79 terial to he nitrated. For nitration mixture we prefer to use. a mixed acid containing about (30% of (36 sulphuric and 40% nitric acid of 1.4 specific gravity. The temperature during nitration should preferably not rise materially above 33 U.v and after the fluid mixture of crude naphthalene and xylene has all been added thereto. agitation is continued for ahont hours to insure substantially completereaction. The agitation is then stopped and the hatch separates into .la'yerst the nitro products containing nit-ronaphthalenei intro-xylene, some unnitrated xylene and the oxidation or nitration products oi various impurities rise to the surface. and are: rapidly and easily separated outxhy drawing of? the acid from heneath. ,The' in'ipurities.am-onipanyingr the naphtha lene and xylene may he certain phenolic oils such as carholic acid and certain other aromatic bases such as pyridene. \\'lll we he lieve to the liquid character o't' the nitrated product and the presence oi some unconverted xylene, the separation is easy and substantially complete-i, 'lherei ore the spent as mixed acid can he readily and safely recov cred and rm-oncentrateil. in the same general manner as is commonly used wilh spent acids used in nitratingcotton.

The fluid mixture oi nitro compounds is run directly into a reducing tank in which ahout 1500 pounds oi the nitro compound mixture are'treated with about 2100 pounds of iron horings or iilin sin the presenw of about 80 pounds'o't an drochloric acid. ahout 3000 pounds of'wa-tei' being added. The batch is agitatedior about 2 hours and. after the reduction is substantially complete as shown by the usual;

test for completeness of reduction, the mix- 11G ture, of amines and associated i'iroduots is. easily separated out still as a fluid. V e pr fer to do this as follows: Add about 120 pounds of lime to the batch and heat the accompanying the com- 60 we sulph'arieger by batchto about loo (3. to neutralize the excess acid therein. The lcntirc charge is then put into a filter press of any suitable kind, to remove the iron sludge. Water and the liquid reduction products pass out through the filter and the substantiall complete re moval of the liquid reduction products from the filtered cake is accomplished by blowing -steam through the filter press for a short time. ()n standing the liquors from the fil tcr press separate into two layers, the upper layer beings-.1 substantially acid-free mixture of the amines, alpha-naphthylamine and xylidine, and other reduction products of the impurities, not injurious to iron containers and havinga very high value as an ore flotation agent, and in such a fluid form that it is very convenient to handle, pump and feed with the ore pulp. as well as to.

distribute and recover. The flotation material is separated from the lower layer by drawing ofl' the lower layer, and any soluble products may be recovered by adding this lower layer to the next reduction mixture.

It will be clear to those skilled in the art that other high molecular Weight hydro carbons may be used, partially or wholly, in stead of the naphthalene or the xylene. In fact, in using the crude bases we do substitute in part, other materials of high. moleclar weight and complex, as .well as of variable composition. Also other methods of forming the amine substitution products may be used. For example, nitrate of soda and sulphuric acid may be used instead of mixed acid, and the reduction may he carried out without intermediate. separation of the nitration products from the acid liquor. Likewise, other neutralizing agents may be used,

but we prefer lime because of its economy. I

Also the amount and nature. of the impurities accompanying the raw materials may vary greatly. Even if it should happen that the raw bases should contain substantially no impurities, the nitration and reduction of the aromatic bases a mixture has important advantages. Therefore, while we ,have described a preferred form of our impro'vements in great detail. we do not desire to be limited to such details or form, since many other changes and modifications may be made and the invention embodied in wide lyf'difi'erent forms without departing from the spirit and scope thereof in its broader aspects.

hat we claim as new and desire to secure by Letters Patent, is:

x 1. A new composition for flotation of ores l)l'lfilhg mixed naphthalene ring, and bed ole ring amido substitution products acco panicd by such impurities as result fromthc nitration and reduction of crude naphthalenc and xylene.

2. A fluid composition for the flotation of 1 sow/4.9

4, A composition for theflotation of ores comprising a mixture of naphthylamine and xylidine accompanied by such. impuritiesas result fromthe nitration and reduction of crude naphthalene and crude xylene to form the amido substitution products.

The process of making ore flotation ma terial, which consists in nitrating and reducing a mixture of crude benzole ring and naphthalene ring bases to form the aniido substitution products thereof.

6. The process of making ore flotation material', which consists in taking a mixture of crude naphthalene and crude xylene and nitrating' and reducing the mixture to form a mixture of naphthylamine and xylidine accompanied by such impurities as result from the nitration and reduction of mixed crude bases.

' 7. The process of making mixed amines which consists in mixing substantial. quantities of a, normally solid aromatic base with a normally liquid aromatic base to form a fluid mixture thereof and nitrating and re ducing, the fluid mixture to form the mixed amlines.

8. The process of making mixed amines, which consists in forming a fluid mixture of different aromatic bases and nitrating and reducing the fluid mixture to form the mixed amines. r i 9. The process of making mixed amines, which consists in nitrating and reducing a mixture ot benzole ring and naphthalene ring bases to form a mixture of the amido substitution products thereof, neutralizing the excess acid in the mixture and sepaiating the aqueous liquor from the mixture.

10. The process of making an ore flotation composition which consists in taking a crude aromatic base and nitrating and reducing the same to form a flotation composition containing a relatively large amount of the aromatic amino accompanied by such impurities as result from the action of the ni trating and reducing operations on the impurities in the crude aromatic base.

Signed at New York, in the county of New York and State of New York this 29th day" of June, A. D. 1920.

ALGAN Ill RSGI-l. MARX HIRSGH. 

